Use of isotopically enriched nitrogen in actinide fuel in nuclear reactors

Abstract

The present invention provides a nuclear fuel comprising an actinide nitride such as 233U, 234U, 235U, 236U, 238U, 232Th, 239Pu, 240Pu, 241Pu, 242Pu, 244Pu, 239Np, 239Am, 240Am, 241Am, 242Am, 243Am, 244Am, 245Am, 240Cm, 241Cm, 242Cm, 243Cm, 244Cm, 245Cm, 246Cm, 247Cm, 248Cm, 249Cm, 259Cm, 245Bk, 246Bk, 247Bk, 248Bk, 249Bk, 250Bk, 248Cf, 249Cf, 250Cf, 251Cf, 252Cf, 253Cf, 254Cf, 255Cf, 249Es, 250Es, 251Es, 252Es, 253Es, 254Es, 255Es, 251Fm, 252Fm, 253Fm, 254Fm, 255Fm, 256Fm, 257Fm, 255Md, 256Md, 257Md, 258Md, 259Md, 260Md, 253No, 254No, 255No, 256No, 257No, 258No and 259No, and optionally fission products such as 97Tc, 98Tc and 99Tc, suitable for use in nuclear reactors, including those based substantially on thermal fission, such as light and heavy water reactors, gas-cooled nuclear reactors, liquid metal fast breeders or molten salt fast breeders. The fuel contains nitrogen which has been isotopically enriched to at least about 50% 15N, most preferably above 95%.

Description

[0001]This application is a continuation-in-part of U.S. application Ser. No. 10 / 879,416, filed Jun. 29, 2004, which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to the field of nuclear fuels for nuclear power plants. Specifically, a fuel comprising an actinide nitride, suitable for use in nuclear reactors, including those based substantially on thermal fission, such as light and heavy water reactors, gas-cooled nuclear reactors, liquid metal fast breeders or molten salt fast breeders, is provided. The fuel contains nitrogen which has been isotopically enriched to at least 50% 15N.[0004]2. Description of Related Art[0005]In a typical nuclear reactor, such as a pressurized water reactor (PWR), a heavy water reactor (HWR) or a boiling water reactor (BWR), the reactor core includes a large number of fuel assemblies, each of which is composed of a plurality of elongated fuel elements or rods. The fuel r...

AI Technical Summary

Benefits of technology

[0017]It is an object of the present invention, therefore, to provide an economical fuel for use in nuclear reactors, including light and heavy water reactors, gas-cooled nuclear reactors, liquid metal fast breeders or molten salt fast breeders.

[0019]It is a further object of the present invention to provide an economical fuel for use in light and heavy water reactors, gas-cooled nuclear reactors, liquid metal fast breeders or molten salt fast breeders, the fuel having the added benefit of reducing the volume of spent fuel discharged from the reactor.

Problems solved by technology

While most second generation plants operate at very competitive power production cost rates, third generation plants have been designed that have increased capacity, a lower cost of generating electricity due to an increased output / investment ratio, and are cost-competitive to build.

Increasing the fuel utilization in a plant by shortening the fuel cycle is a widely recognized method, but shorter fuel cycles often result in higher production costs and more spent fuel waste discharge.

Initiatives to decrease the rate of spent fuel production by increasing the discharge burnup is limited by fuel rod clad corrosion as well as by limits on fuel enrichment imposed by spent fuel pool considerations and fuel production plant limitations.

Unfortunately, this results in a shorter fuel cycle, due to the very high rate of usage and the fact that there is somewhat less uranium in the core than when solid pellets are used.

Decreasing the enrichment saves money because the cost of enriched fuel increases non-linearly with enrichment.

That is, increasing the enrichment from 4% to 5% increases the cost for the uranium by more than 25%.